Every since I've been trying to download niche-er torrents with few seeds I noticed this issue cropping up occasionally:

[22:55:11]  tracker announcing  >
[22:55:14]  tracker responded OK, returned=0  seeds=1  peers=1  interval=45:01 >

Emphasis mine. The torrent has seeds, by all accounts they are connectable and active (based on the peerlist on the website in question), but announcing returns none and the peerlist is empty.

Any ideas? Is this a client issue? Is this is a tracker issue? Is it a firewall issue? Any ideas at all?

Thanks

You can announce to a tracker that you are a seed. Its just a URL escaped text string.
When you disconnect and reconnect, and you START in Tixati it will pop up the peers. If there is a peer it will connect for your interval (default 15-30 seconds) you want to keep track of that info.
Try searching DNS cache for the IP. It's possible it is not connectable. Are you connectable? Default I think is OUTBOUND first, i.e. failure if THEY are behind firewall. THEN after your IP is in the list the peer will re-announce and try to connect you. You will see the PEER list tag "I" for incoming.